Endothelin-1 (ET-1) is a potent vasoconstrictor that is secreted by vascular endothelial cells. ET-1, ET-2, ET-3, and endothelin β are members of a family of related peptides. All are 21 amino acid peptides with two disulfide bridges. ET-1 and ET-2 differ by only two residues, while ET-3 differs from both by six residues. ET-1 and ET-2 are highly effective on vascular smooth muscle, while the effects of ET-3 are minimal. ET-1 and its precursor, big ET-1, are the primary forms present in the circulation. Circulating ET-1 plays a pathologic role in the etiology of hypertension and antagonists are utilized in the treatment of this disease. The ET-1 receptor is a seven-transmembrane-domain receptor of the G-protein-coupled family that signals via transient increases in intracellular Ca2+. It is primarily expressed in lung and heart and is detected at lower levels in liver, brain, muscle, and kidney. ET-1 receptor interacts with ET-1, ET-2, and ET-3. However, it has a 2-3 fold higher affinity for ET-1 than ET-2 and the affinity for ET-3 is more than 100 fold lower. Thus, ligation of the ET-1 receptor by ET-1 induces increased intracellular Ca2+ that signals to promote vasoconstriction.
This antibody is routinely tested by western blot analysis. Other applications were tested at BD Biosciences Pharmingen during antibody development only or reported in the literature.